"The ultimate sword... graze someone's toe with this... instant death." -Drach about the Scourge
The Scourge of Blood is a very powerful Heliosatanic relic sword capable of bringing instant death to any target by atomizing them. It's exact material is still unknown as its creators died off millions of years ago and no one has gotten close enough to study it and it was modified some time after the First Battle for Earth.
The Scourge of Blood was created to battle a deadly threat to the universe, the Corrupt Passage by the Heliosatan's expert weapon smiths. It worked but almost immediately after the Corrupt War, it, along with the approximately five million other relics fell into the wrong hands and were used to eliminate half the Heliosatan civilian population before the wielders were finally killed. After the last one was secured, the Heliosatan leader ordered every single relic to be sent out into other unpopulated planets, so an event of this magnitude could never happen again. The Scourge ended up on Earth, or at least the meteorite that would hit it.
After the First Battle for Earth, a human mining crew in Nevada finds it and they only know it's a sword, and otherwise have no idea what it is, one tries to pick it up and is instantly atomized. Drach hears about it on the news and knows instantly what it is, before his exile, he'd heard tales about the relics and that the Scourge of Blood and Devastation of Soul, a particle gun, were the two most powerful weapons in existence. He begins the journey, skimming the ground in a Slicer, a fast ground vehicle and arrives within three hours, despite having to travel all the way from Chicago. He quickly finds it and installs a safety mechanism on it.
Back at the base, Laval notices the sword and tries to pick it up. He says to himself that it doesn't look sharp enough for a sword. Drach overhears and explains. It isn't sharp because it doesn't need to be, just touch an enemy with it and they disintegrate, touch an ally and it phases through them, if an enemy tries to pick it up, they disintegrate.
The sword's name is a reference to Scourge from BloodClan, an evil cat from the Warriors saga by Erin Hunter.
A scourge is a whip used for punishment, making its name ironic.